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    <title>Document</title>
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<body>
    <script>
        // 1.创建FormData实例
        var fd = new FormData()
        // 2.调用append函数，像fd中追加数据
        fd.append('uname','zs')
        fd.append('upwd','123456')

        var xhr = new XMLHttpRequest()
        xhr.open('POST','http://www.liulongbin.top:3306/api/formdata')
        xhr.send(fd)

        xhr.onreadystatechange = ()=>{
            if (xhr.readyState === 4 && xhr.status === 200) {
                console.log(JSON.parse(xhr.responseText));
            }
        }
    </script>
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